Examples of airbags include an airbag that is folded and housed inside an instrument panel (hereinafter suitably “IP”). This airbag starts to inflate from the instrument panel upper surface when injected with high-pressure gas from the inflator, continues to inflate and deploy toward an occupant as it unfolds, and then is received by the occupant.
Known airbags of such a configuration include a so-called twin airbag that comprises a left airbag portion and a right airbag portion, and receives an occupant via a depression formed between the left and right airbag portions in an inflated and deployed state (see JP, A, 2008-62710, for example). This twin airbag is formed as a bag body wherein an outer panel and an inner panel are connected by a seam.